From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Daney Subject: Re: [PATCH v6 2/3] MIPS: OCTEON: Rename legacy properties in internal device trees. Date: Thu, 11 Feb 2016 08:32:46 -0800 Message-ID: <56BCB7AE.2050901@gmail.com> References: <1455207976-2262-1-git-send-email-matt.redfearn@imgtec.com> <1455207976-2262-2-git-send-email-matt.redfearn@imgtec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1455207976-2262-2-git-send-email-matt.redfearn@imgtec.com> Sender: linux-mmc-owner@vger.kernel.org To: Matt Redfearn Cc: david.daney@cavium.com, aleksey.makarov@caviumnetworks.com, ulf.hansson@linaro.org, robh@kernel.org, ralf@linux-mips.org, linux-mmc@vger.kernel.org, linux-mips@linux-mips.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On 02/11/2016 08:26 AM, Matt Redfearn wrote: > Many OCTEON devices have been shipped in products with fixed DTBs. These > DTBS contain properties which are not compatible with newer kernels with > upstream drivers. > Therefore some mechanism is necessary to convert legacy naming into > upstream naming. In the first instance this is to support the OCTEON MMC > controller, which is in a later patch of this series. > This patch adds a octeon_handle_legacy_device_tree() function which is > always called from device_tree_init() to fix up the device tree so that > drivers need have no knowledge of the legacy naming or properties. > > Signed-off-by: Matt Redfearn NAK... I already sent e-mail on this, but it crossed in flight. Basically, this patch is much more complex than the original code which was just a few lines to check the alternate "legacy" names. Also this code is prone to breakage, see below... > --- > For reference, the legacy MMC bindings are as follows. Only the > spi-max-frequency and bus-width properties currently need renaming. > > mmc: mmc@1180000002000 { > compatible = "cavium,octeon-6130-mmc"; > reg = <0x11800 0x00002000 0x0 0x100>, > <0x11800 0x00000168 0x0 0x20>; > #address-cells = <1>; > #size-cells = <0>; > /* EMM irq, DMA irq */ > interrupts = <1 19>, <0 63>; > > /* The board only has a single MMC slot */ > mmc-slot@2 { > compatible = "cavium,octeon-6130-mmc-slot"; > reg = <2>; > voltage-ranges = <3300 3300>; > spi-max-frequency = <26000000>; > /* Power on GPIO 8, active high */ > /* power-gpios = <&gpio 8 0>; */ > power-gpios = <&gpio 8 1>; > > /* spi-max-frequency = <52000000>; */ > /* bus width can be 1, 4 or 8 */ > cavium,bus-max-width = <8>; > }; > mmc-slot@0 { > compatible = "cavium,octeon-6130-mmc-slot"; > reg = <0>; > voltage-ranges = <3300 3300>; > spi-max-frequency = <26000000>; > /* non-removable; */ > bus-width = <8>; > /* bus width can be 1, 4 or 8 */ > cavium,bus-max-width = <8>; > }; > }; > --- > arch/mips/cavium-octeon/octeon-platform.c | 57 +++++++++++++++++++++++++++++++ > arch/mips/cavium-octeon/setup.c | 3 ++ > 2 files changed, 60 insertions(+) > > diff --git a/arch/mips/cavium-octeon/octeon-platform.c b/arch/mips/cavium-octeon/octeon-platform.c > index d113c8ded6e2..7933978bdfa5 100644 > --- a/arch/mips/cavium-octeon/octeon-platform.c > +++ b/arch/mips/cavium-octeon/octeon-platform.c > @@ -980,6 +980,63 @@ end_led: > return 0; > } > > +/* > + * Rename a DT property from legacy to upstream accepted name. > + * The value is copied from old legacy name to new name. > + */ > +static void __init octeon_fdt_renameprop(int node, const char *old, const char *new) > +{ > + const u32 *pv; > + u32 v; > + > + pv = fdt_getprop(initial_boot_params, node, old, NULL); > + if (pv) { > + v = *pv; > + fdt_delprop(initial_boot_params, node, old); > + fdt_setprop_u32(initial_boot_params, node, new, v); > + } > +} > + > +/* > + * This function is called for every machine type to replace legacy entries > + * in the device tree blob passed from older firmwares. > + * It is impractical to change the DTB in shipped devices, but to support newer > + * kernels with upstreamed drivers and DT bindings some massaging of the DTB > + * must be done. > + */ > +int __init octeon_handle_legacy_device_tree(void) > +{ > + const char *alias_prop; > + int aliases; > + > + if (fdt_check_header(initial_boot_params)) > + panic("Corrupt Device Tree."); > + > + aliases = fdt_path_offset(initial_boot_params, "/aliases"); > + if (aliases < 0) { > + pr_err("Error: No /aliases node in device tree."); > + return -EINVAL; > + } > + /aliases doesn't exist on many boards, so this will likely fail. > + /* MMC */ > + alias_prop = fdt_getprop(initial_boot_params, aliases, > + "emmc", NULL); > + if (alias_prop) { > + int mmc = fdt_path_offset(initial_boot_params, alias_prop); > + int slot = fdt_first_subnode(initial_boot_params, mmc); > + > + while (slot > 0) { > + octeon_fdt_renameprop(slot, "cavium,bus-max-width", > + "bus-width"); > + octeon_fdt_renameprop(slot, "spi-max-frequency", > + "max-frequency"); > + slot = fdt_next_subnode(initial_boot_params, slot); > + } > + } > + return 0; > +} > + > + > static int __init octeon_publish_devices(void) > { > return of_platform_bus_probe(NULL, octeon_ids, NULL); > diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c > index cd7101fb6227..f1f5191d02be 100644 > --- a/arch/mips/cavium-octeon/setup.c > +++ b/arch/mips/cavium-octeon/setup.c > @@ -1080,6 +1080,7 @@ void __init prom_free_prom_memory(void) > } > > int octeon_prune_device_tree(void); > +int octeon_handle_legacy_device_tree(void); > > extern const char __appended_dtb; > extern const char __dtb_octeon_3xxx_begin; > @@ -1112,6 +1113,8 @@ void __init device_tree_init(void) > > initial_boot_params = (void *)fdt; > > + octeon_handle_legacy_device_tree(); > + > if (do_prune) { > octeon_prune_device_tree(); > pr_info("Using internal Device Tree.\n"); >